Coal burning automatically fired hot water heater



Dea. 27, 193s.

W. A. RIDDELL COAL BURNING AUTOMATICALLY FTRED HOT WATER HEATER Filed Dec. 12, 1955 4 sheets-Snead Dec. 27, 1958., w. RIDDELL COAL BURNING AU'IV'OMATICALLY FIRED HOTl WATER HEATER Filed Dec..

4 Sheets-Sheet 2 m L 2 MLU/mf-- w 0.0 .m ww.

Dec. 27, 1938. i I w. A.- RIDDELL 2,141,764

.COAL BURNING lAUTQMTIGALLY FIRED HOT WATER HEATER Fiied Dec. 12,l 193s I 4 sheets-sheet 3 E 57 INVENTOR` Dec. 27, 193s.

W. A. RIDDELL COAL BURNING AUTOMATIGALLY FIRED HomwATEB HEATER' Filed lDeo. l2, 1936 4 Sheets-Sheet 4 Patented Dec. Z7, 1938 UNITED STATES amm COAL BURNING AUTOMATICALLY FIRE) HOT WATER HEATER WilliamA. Riddell, Frederick, Md., assignorto The General Engineering Company, Frederick, Md., a corporation of Maryland Application December 12, 1936, Serial No. 115,594

Claims.

My invention relates broadly to coal burning automatically fired hot water heaters and more particularly to a construction of hot water heater in which Water may be economically heated in 5 relatively large quantities.

One of the objects of my invention is to provide a construction of hot water heater in which water is heated by combustion of coal as distinguished from gas or electricity usually employed in hot' AWater heaters. 4 Another object of my invention is to provide a construction of coal fired hot water heater in which a combustion chamber designed especially for heating water may be fired with coal which is automatically supplied to the combustion chamber.'. l v

Still another object of my invention is to provide a construction of coal burning automatically red hot water heater in which the combustion cham- 20 ber may be compactly assembled with respect to a coal feeding hopper and a hot Water storage tank for insuring a continuous supply of hot water.

A further object of my invention is to provide a 25 construction of intermittently operated coal burning Stoker providing heating means for a water jacketed combustion chamber of diminutive size operative for heating relatively large quantities of hot water.

A still further object of my invention is to provide a coal fired hot water heater of diminutive size mounted upon a support so arrangedthat an ash can may be arranged directly beneath the combustion chamber and the residue from the combustion chamber conveniently removed from .time to time with minimum elort.

Another object of my invention is to provide a construction of coal burning automatically red hot Water heater inwhich the transverse section of the hot water heater substantially conforms in size to the diameter of the ordinary ash can and in which the combustion chamber is sufficiently elevated from the supporting floor as to allow the ordinary ash can to be conveniently inserted or removed from a position beneath the Stoker.

Still another object of my invention is to provide a construction of diminutive coal burning stoker for hot Water heaters having special provision for preventing the escape of gases from the combustion chamber through the coal feeding tube and through the coal feeding hopper.

Other and further objects of my invention reside in the construction of diminutive coal burning automatically fired hot water heater as 55 set forth in the speccation hereinafter following and as illustrated in the accompanying drawings in which:

Figure 1 is a front elevational view of a hot water heating plant showing the diminutive hot water heater and diminutive coal feeding stoker 5 associated therewith and illustrating the comparative size thereof with respect to the ordinary hot-waterstorage tank; Fig. 2 is a View similar to the view illustrated in Fig. 1 looking in the direction of the rear of the coal burning automatically 10 fired hot water heater of my invention; Fig. 3 is a central vertical longitudinal sectional view taken-on line 3 3 of Fig. 4 on an enlarged scale through the diminutive hot water heater and associated coal feeding hopper and diminutive l5 Stoker for feeding coal to the combustion chamber of the hot water heater and illustrating more vparticularly the general arrangement of the coal feeding conveyorand the arrangement provided for preventing the escape of gases through the '4 coal feeding conveyor or'storage hopper; Fig. 4 is aA horizontal sectional View taken online 4 4 of Fig. 3; Fig. 5 is a transverse vertical sectional view taken on line 5 5 of Fig. 3 and showing more particularly the arrangement of the water. jacketed sections of the hot water heater, the mechanism operatingthe coal feeding conveyor and the mechanism for establishing the required draft for promoting combustion; Fig. 6 is a. horizontal sectional view through the hot water heater, the coal feeding hopper and the hot water storage tank taken substantially on line 6 6 of Fig. l but illustrated in enlarged size; Fig. 7 is a similar view taken on line 1 1 of Fig. 3 and showing more particularly the support for the hot water heater and the removable ash can f or receiving residue from the heater; Fig. 8 isa fragmentary enlarged sectional view taken through the coal feeding tube and showing the coal feeding conveyor therein and illustrating one of the means provided for preventing the escape of gases from the combustion chamber through the coal feeding tube and through the coal feeding hopper; Fig. 9 is a transverse sectional view taken on line 9 9 of Fig. 8; Fig, 10 is a top plan view of the arrangement for 45 preventing escape of gases illustrated infFigs. 8 and 9; Fig. 11 is a fragmentary horizontal sectional vieW taken on line I I ll of Fig. 9; and Fig. 12 is a perspective view of the ash removal door employed in the construction of my invention.V

My invention is directed toa diminutive construction of coal burning automatically fired hot water heater designed to heat relatively large quantities of hot water at extremely low cost.

'I'hepexpense of gas operated hot water heaters or electrically operated hot water heaters in heating quantities of water normally required for consumption is often quite substantial, Eiorts have been made to decrease the cost of heating water by employing special constructions of oil burners and/or oil burners which form a part of the usual hot water or steam heatingsystem. Both the initial and operating costs however, are quite substantial. Various constructions of kerosene operated hot water heaters have been proposed, but because of the nature of the fuel and the odors incident thereto, the operation of such burners is not always satisfactory. Thevinitial cost of kerosene operated, oil fired, gas and electrically operated hot water heaters is normally large and the operating expense substantial.

The coal burning automatically ired hot Water heater of my invention on the contrary, is relatively low in its initial installation cost, and may be operated to supply all normal requirements at a cost which, in the case of domestic installations, often does not exceed ninety cents a month. Automatic operation of the coal feeding mechanism may be effected by any suitable thermostatic control connectedwith the hot water boiler, and safety devices of similar type connected in the ue and the water supply line may also be employed.

In the structure of my invention, I provide a support which is slightly larger than the usual ash can and over which the automatically fired hot water heater is mounted. The normal size ash can may accordingly, be moved into position beneath the -automatically red hot water heater to receive the residue from the coal fired burner and when filled, readily withdrawn and emptied and reinserted in position. The burner requires very little attention as coal is supplied at infrequent intervals and the ash can fills slowly. The hot Water heater is mounted above the ash receiving receptacle and consists of a multiplicity of transversely arranged water jacketed sections. the water jacketed sections from an inlet connection leading from the hot water storage tank to an outlet connection which returns to the hot water storage tank. Passages for the products of combustion are provided through the water jacketed sections to insure maximum absorption of heat by the water from the combustin chamber in the course of circulation of the water through the water jacketed sections. The automatically red coal burning equipment projects into the combustion chamber -from one side of the frame support and is connected with a coal feeding hopper which is substantially the size of the hot water heater per se. A motor driven mechanism is provided for operating a screw conveyor for advancing the coal from the coal feed'- ing hopper to the grate within the combustion chamber. The grate is centrally positioned within the combustion chamber and is peripherally supported in spaced relation to the Water jacketed side walls of the combustion chamber. I provide means directly over the grate for preventing the coking of the coal in the course vof combustion. Air is supplied under pressure beneath the grate and projected through apertures therein for regulating the rate of combustion and facilitating burning of the coal. through which the conveyor operates, is constructed in a very special manner to insure the return .of gases which may tend to leak through the coal feeding tube for seepage through the coal I tion 4.

Water is circulated through The coal feeding tube,Y

feeding hopper, to the combustion chamber. I provide paths for the return of gases which may tend to leak through the coal feeding tube in at least two spaced zones along the tube for insuring the operation of the coal burning mechanism with substantially no odors whatever. The stoker mechanism is designed for extremely quiet operation so that the apparatus of my invention provides an ideal installation for domestic use Without substantial inconveniences and of highly economic characteristics.

Referring to the drawings in more detail, reference character I designates the furnace unit of the hot water heater, consisting of the water jacketed header 2, the intermediate water distributing head 3, and the water jacketed wall sec- The header 2 is provided with radially projecting lugs 2a thereon aligned with similarly formed lugs 3a on the distributing head 3, and correspondingly positioned lugs 4a on the Water jacketed wall section 4. Bolts 5 extend through the aligned lugs 2a, 3a, and 4a for securing the water jacketed Wall section 4, the intermediate distributing head 3, and the header 2 in position with the joints therebetween cemented as indicated at 6. The water jacketed wall section 4 is provided with an annularly flanged base 1 by which the hot water heater is supported on flanges 36 and 39 of the complementary sections 32 and 38 of the supporting means.. The water jacketed Wall section 4 is provided with circulating passages for Water indicated at 8. The intermediatel water distributing head 3 is provided with a serppntine passage for Water indicated at 9. The header 2 is also provided With a serpentine passage for water as indicated at I0, the passages being aligned and interconnected by means of liners 28. The hot Water outlet for the hot water heater is indicated at Il, while the cold water intake is shown at I2 connected with appropriate positions on the hot Water storage tank I6. That is, the cold water intake I2 is connected with the hot water storage tank I6 through cold water connection I4 and valve l5. The cold water connection for the hot water storage tank is indicated in Figs. 1' and 2, at I1, while the hot water outlet for storage tank I6 is shown at I8. The

support for the hot water storage tank is shown head 3. A serpentine passage for the productsA of combustion is provided through intermediate water distributing head 3 and header 2 as indicated at 24 and 25, registering with the discharge passage 26 for the products of combustion arising from combustion chamber 21. A stack 29 is connected through outlet 36 with the header 2 as shown. A damper 3i is mounted in stack 29 for controlling the draft through the furnace.

The support for the furnace structure comprises the interconnected frame members 32 and 38 which are interconnected by abutting vertically extending fianges 31 and 40 interconnected by bolts 42. The Wall section 32 has a transversely extending flange 36, while wall section 38 has a transversely extending flange 39, which engage ange 'I of the hot water heater and support the hot water heater by interconnecting bolts The wall section 32 is provided with'a basev rigid connection with respect to the foundation or floor 44. The wall section 38 is provided with a base flange 43. Both the base flanges 43 and 33 extend laterally for forming a base support 35 for the ash can beneath the grate.

In order to afford access to the ash receiving receptacle which I have shown at 49, I provide a removable front structure 45 having a pair of side flanges adapted to engage the sides of the wall section 38. The wall section 38 is shaped to provide a substantially rectangular front portion for the furnace support. Pins -48 project 'from the opposite sides ofthe wall section 38 and provide "means for engagement by the bayonet slots 41 in the side flanges of the removable door 45. A handle 46 is provided on removable door 45 to facilitate the removal and replacement of the door by a quick vertically upward or downward movement. The ash receiving receptacle or ash can 49 is provided with handles 58, which allow the receptacle to be readily inserted or removed beneath the coal burning grate.

The automatically fired coal burner is symmetrically balanced on the wall support 32. The parts of the stoker, the grate, the air supply means, the coal feeding hopper andthe driving means for the screw conveyor are so proportioned that a substantially equal mass projects interiorly and exteriorly of the furnace allowing the balancing of the entire structure on the side wall of the furnace support. I provide a single casting constituting the base of the coal feeding hopper indicated at and including the conveyor tube 5'2 formed with a tunnel section 61 connected to the wall section 53, and the support 54 for the drivvflange 56 of vertical wall section 32 at one side and by means of flanges 51 and 58 with the coacting flanges 1 and 36 of the hot water heater and the vertical wall section 32 respectively. Bolts 4| interconnect flanges 1 and 51. Bolts 59 interconnect iianges 36 and 58. Flanges 55 and 56 are interconnected by means of bolts 68. The air supply conduit 6| is also supported by the vertical wall section 32. The air supply conduit 6| is provided with a wall section 62 flanged at 63 which on one side interconnects with coacting iiange 55 and on the other side interconnects co"- acting flange 64 of vertically extending Wall section 32. Bolts 65 maintain flanges 64, 63 and 55 in interconnection. An extension 66 of the air supply conduit is formed integral with the. air distributing chamber 69 and connected with the conduit 6| at the wall section 62. The lower portionof flange 63 abuts against the recessed Apor-v tion of flange 36 coextensive with the vertical flange 64. The coal conveying conduit or tunnel member 61 is aligned with the tunnel section of the conveyor tube 52 interiorly of the wall structure 32 with fiange68 thereof secured to the inner face of the wall section 53. The coal conveying tunnel member 61 is integrally connected with the air dist;ibuting chamber 69 lor cated beneath the grate 18.

The grate is perforated at 1| for permitting the forced distribution of air through the fuel bed supported thereon.

A peripheral ange 12 is provided on the grate 10 which coacts with the i projects through an aperture in the bottom of air distributing member 69 and engages screw threads in a screw threaded recess in the member which forms the grate 18. The member which constitutes the grate 18 has an integrally formed tubular portion 16 which engages an annular seat 11 aligned with the coal conveying conduit 61. The aligned conveyor tube 52, coal conveying conduit 61 and tubular portion 16 form a tunnel or straight passage through which the screw conveyor, which I have indicated at 18 is adapted to operate. The screw conveyor 18 is driven through coupling 19 and shaft 88 by means of sprocket wheel 8| driven by sprocket chain 82 from driven member 83.v Driven member 83 is operated through a reduction gear system indicated generally at 84,which is in turn driven by motor 85. Motor 85 is suitably mounted on support 54 depending from the base of the coal feeding hopper indicated at 5| The chain 82 and coacting sprocket wheel are guarded from external contact with any obstructions by means of a suitable shield 86. Shield 86 is connected by bolts 81 to the coal feedingl hopper indicated at 5|.

Motor 85 also serves as a means for driving the fan 88. which is openat one side as indicated at 90. The opening 90 inthe side wall of the fan housing may bc regulated by means of a suitable shutter 9| by which the desired amount of air may be regulated. The fan housing 89 is connected through the coupling indicated at 92 with the air supply conduit 6| by which air is supplied under pressure to the air distributing chamber 69 beneath the grate 10. The fan housing 89 is supported from the base of the coal feeding hopper indicated at 5| by means of interconnecting flange 92 and bolts 93.

Immediately above the gra-te 18, I provide a ame spreading device 94 which is suspended from the upper portion of the water jacketed wall section 4 by means of screw threaded member 95' extending into screw threaded socket 96 in the upper interior head of the water jacketed section 4 and connected at the lower end with flame spreading device 94 screw threaded thereon as indicated at 91. The flame spreader 94 is perforated at 98 for allowing circulation of heat through the combustion chamber over the lire bed. The flame spreader also serves as means for breaking up fuel which may tend to coke and impair the ysteady combustion of fuel.

The coal hopper is represented at 99 into which a sufficient supply of coal is deposited to enable the burner to operate over relatively long time periods without refueling. The burner of my invention is particularly adaptable for the burning of Rice Anthracite coal.

I provide a special construction of coal handling mechanism for avoiding the tendency of gases to leak backward through the coal feeding tube and upwardly through the coal in the hopper. Referring toFigs. 3, 6, and 8-11 it will be observed that the coal conveying tube 61 is distorted in shape to provide an upwardly projecting pocket |88. The pocket |88 servesas a gas collecting chamber for receiving gases which.

The fan 88 is disposed in housing 89 hood H12V is attached to the top of the chamber W by means of screws IUS and serves as a guard for preventing coal, ashes, dust, dirt, or other matter from falling into the apertures IDI and clogging the apertures. The device I02`serves in the nature of a hood or umbrella over the apertures ll for preventing the clogging of the slots while allowing return of gases from within chamber |00 to the combustion chamber 21.

In order to further prevent the seepage of gas through the coal conveyor tube 52, I provide in wall section 53 a gas release aperture IM adjacent the top thereof. A second gas collecting chamber is virtually formed adjacent the wall section 53 and confined by the downwardly extending protective wall or hood |05.' Gases which might tend to pass the rst gas collecting chamber |00 are caught at the second gas collecting chamber indicated at |06 and returned through passage IM to the combustion chamber. Accordingly leakage of gases through' the coal in the hopper 89 is wholly prevented.

I have found the coal burner of my invention highly practical in its manufacture, production, installation and use. The operation of the coal burner is very economical and convenient. The entire structure including the hopper and combustion chamber is selfcontained and is readily installed in proper relation to the ash receiving receptacle above the floor level. 'I'he equipment is suitable for restaurants, apartment houses, domestic use and for many other purposes. I have described by invention in one of its preferred embodiments but I desire that it be understood that modications may be made within the scope of the appended claims and that no limitations upon my invention are intended otherv than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

l. In combination, a furnace including a combustion chamber, and an underfeed coal stoker having a grate portion disposed within said combustion `chamber in limited spaced relation to the Walls of said chamber, a coal storage hopper exterior of said furnace, a fuel conveying tube provided with fuel propelling means interconnecting said hopper and said grate, said fuel conveying tube having a wall portion exposed within said combustion chamber with openings there`r in directly communicating With said combustion chamber whereby gases accumulating in said fuel conveying tube may pass directly into said combustion chamber beneath the level of said grate, and shield means for protecting the openings in said fuel conveying tube from stoppage by ashes discharged by said grate while permitting escape of gases into said combustion chamber.

2. In combination, a furnace and stoker as agence set forth in claim l, and additional means pr-l viding an opening from said fuel conveying tube immediately adjacent said hopper into said combustion chamber, whereby gases accumulating near the entrance to said fuel conveying tube adjacent said hopper may pass directly into said combustion chamber.

3. In combination, a furnace. and stoker as set forth in claim l, and additional means providing an opening from said fuel conveying tube immediately adjacent said hopper into said combustion chamber, whereby gases accumulating near the entrance to said fuel conveying tube adjacent said hopper may pass directly into said combustion chamber, said means including a gas collecting chamber communicating with the said fuel conveying tube, the last said opening being disposedin a wall of said gas collecting chamber in a position protected from ashes discharged by said grate.y

4. A hot water heater comprising a supporting wall structure and a boiler mounted thereon, said Wall structure having a flanged opening therein, a coal feeding hopper including a tunnel section having an integral ange portion secured in the flangedA opening in said wall structure for supporting said coal feeding hopper exteriorly of said boiler, an adjoining tunnel member having an integral flanged terminus secured to the tunnel section of said coal feeding hopper for supporting said tunnel member interiorly of said boiler, and a grate member secured at the opposite terminus of said tunnel member and opening within said boiler.

5. In a boiler and stoker combination including a coal feeding hopper mounted exteriorly of said boiler, a tunnel member mounted in direct connection with said coal feeding hopper and comprising a tunnel portion terminating in an integral substantially circular chamber portion opening within said boiler, a perforated grate member mounted in said chamber portion in communication with said tunnel portion in a ver.- tical plane at the junction of said tunnel and chamber portions and providing a i'lrebed and outlet Within said boiler for fuel conveyed from said hopper through said tunnel portions, means for supplying air to said perforated grate member through the chamber portion of said tunnel member, said chamber portion and said perforated grate member having coacting peripheral flanges at the openings thereof within the boiler, and means extending through the bottom of said chamber portion and engaged with the bottom of said grate member for maintaining said flanges in close contact and flxedly mounting said grate member in said chamber portion in communication with said tunnel portion.

. WILLIAM A. RIDDELL. 

